This invention relates to the underground laying of cables such as fiber optic cables in which the cable must be unwound from a reel when an obstruction is encountered and then rewound after an end of the cable is fed under or through the obstruction, and more particularly, to apparatus for automatically performing the unwinding operation in a rapid and efficient manner.
A well-known problem in the laying of underground cables, including fiber optic cables, is how to lay the cable under an obstruction. Encountering a roadway or similar obstacle through which a trench could not be conveniently routed, has meant that a tunnel or bore has had to be driven under the obstacle. This further involved the necessity of unwinding the cable from a storage reel, feeding the free end of the cable through the tunnel, and then rewinding the cable back unto the reel on the other side of the obstruction. This operation has involved considerable man-hours of effort and the tortuous laying of cable on the ground in various patterns so that the cable could be more readily rewound.
Different devices for handling cable are known in the art. See, for example, U.S. Pat. Nos. 4,744,696, 4,701,098, 4,568,035, 4,542,861, 4,454,999, 4,447,013, and U.S. Pat. No. 4,338,059. In addition to these, there is also U.S. Pat. No. 4,871,127, which discloses a portable device for storing an endless cable. The device includes a slotted center tube in which the clack end of a cable is installed. The cable is also looped inside a reel and transversely inserted into a bail and snatch blocks. A drum is then rotated and reciprocates such that the cable is wound onto the reel. While the device does alleviate some of the problems described above, including reducing the time and man-hours required to unwind a cable, other apparatus should be available which is simpler to use, and as cost effective. Furthermore, it is a requirement of the shown device that the cable must always be centrally oriented, and threaded through the center of the device to operate.